Method for producing a continuous waterproofing flooring

ABSTRACT

The subject matter of the present invention is to provide a method for producing a continuous waterproofing flooring. This method consists in waterproofing a foundation ( 2 ) with the following coupled system: a) two component liquid applied waterproofing membrane ( 3 ) based on a hydraulic binders, with or without reinforcing fibrous base layer or mailing ( 4 ), that provides for water vapor permeability and watertightness; b) polymer-based coating ( 6 ), with or without aggregates, constituting the visible side of the walkable and vehicle-suitable flooring, characterized by high water vapor permeability. The flooring thus obtained is a continuous flooring with characteristics of high water vapor permeability and watertightness and characterized in that it&#39;s nonslip, self-cleaning, not subject to yellowing, wear and tear resistant.

Nowadays, in the building industry, the waterproofing of flat roofs,terraces, balconies and the like is performed by various methods, whichcan be distinguished according to the chemical nature of the covering.We'll now briefly analyse the performances of such covering in order tohighlight those limitations which can be overcome by the presentinvention.

Bitumen-Based Waterproofing Sheets

Bitumen-based waterproofing sheets are usually fixed to the roof bymeans of flame heating or self-adhesive systems. During manufacturingthey can be coated with protective elements, as foils or coloured marblechips. These elements improve the appearance, the weatherability, thewear resistance and the tear resistance of the sheet. Nevertheless thismaterial can't be considered a pedestrian or vehicle-suitable floorcoating because of thermoplastic behaviour of bitumen with increasingtemperature; in the summer, indeed, bitumen-based sheets, even thoughprotected, are damaged and deformed by pedestrian or vehicle traffic.This material, moreover, is not water vapor permeable, so that it'simpossible also for very small amount of liquid water to evaporate fromfoundation.

Polyvinylchloride-Based and Olefinic Rubber-Based Waterproofing Sheets

This material is made of very wide prefabricated rolled up sheets andit's sufficient to lay them on the roof, without any adhesive system,and cover them with gravel or earth to prevent any movement. But if youwant to make a concrete or tile flooring on this waterproofing material,you have not negligible additional cost due to the high cost of manuallabour. Furthermore, neither of these sheets possess enough water vaporpermeability to allow even the slightest percentage of water evaporationfrom foundation.

Resin-Based Waterproofing Materials (Two-Component ElastomericPolyurethane, One-Component Urethane, Two-Component Epoxypolyurethane,Polyester, Two-Component Silicone Resins and Neoprene Resins)

These materials possess characteristics of application that get close tothe subject matter of the present invention; however, they show thefollowing disadvantages:

-   i) insufficient water vapor permeability to allow application on wet    foundation (if applied at this condition, bubble forming and    detachment of the resin coating from the lower layer will occur);-   ii) high cost of raw materials;-   iii) need of applying more than one coating of resin and aggregates,    thus increasing manual labour cost;    Flexible Two-Component Methacrylic Resin-Based Waterproofing    Materials

These materials possess characteristics of application that get close tothe subject matter of the present invention; however, they show thefollowing disadvantages:

-   i) difficulties of application on very porous foundation (these    materials are not fit to permeate and strengthen surfaces that will    eventually have little cohesion);-   ii) high cost of raw materials;-   iii) high flammability of the components;-   iv) high vapor pressure of the methacrylic monomer which implies a    remarkable spreading of vapor and smell in the building site and the    surroundings;-   v) a marked tendency of the coating to yellowing.    Latex-Based Waterproofing Membranes (Acrylic Esters,    Styrene-Acrylate, and Acrylonitrile Latices)

These materials are a considerable part of the liquid appliedwaterproofing products in today's market. They show the followingdisadvantages:

-   i) insufficient permeability to water vapor to allow application on    wet foundation (if applied on these conditions, bubble forming and    detachment from foundation will occur);-   ii) minimum film forming temperature higher than +7++8° C.;    Liquid Applied Waterproofing Membranes Based on Cement-Latex Mix

These materials are constituted by a powder part containing a cementbinder, and by a conveniently formulated liquid part containingpolymeric latices. The waterproofing system thus obtained guarantees thepermeability to water vapor and the impermeability to liquid water, butit cannot be considered flooring system since it does not possess enoughaesthetic characteristics and tear resistance; therefore it is necessaryto apply a protective finish (e.g. tile covering).

There are patents that deal with continuous waterproofing coveringsystems and refer to the use of materials and to the limitations abovementioned.

Accordingly, mention is made of U.S. Pat. No. 4,588,458, which disclosesthe use of a waterproofing membrane composed by a fibrous reinforcingbase layer or matting impregnated with thermoplastic polymers-bitumenmix; GB 2193153, which discloses the use of a water vapor permeable feltconstituted by non-woven fabric impregnated with bitumen on whoseunderside a film of perforated plastic material is applied, and then athin metal layer; U.S. Pat. No. 4,897,313, which discloses the use of awaterproofing system composed by a first coating of butyl acrylate,styrene and acrylonitrile copolymer latex, and a prefabricatedself-adhesive sheet of bitumen modified with elastic polymers; WO01/72514, which discloses the use of covering panels composed by anupper coating of acrylonitrile, styrene and acrylic esters copolymersand of a lower coating of polyvinylchloride; U.S. Pat. No. 5,422,179,which discloses the use of waterproofing polymeric sheets obtained bycopolymerization of ethylene, vinyl esters and acrylic esters; DE3342560, which discloses the use of waterproofing sheets made ofolefinic rubber strengthened with a fibreglass matting; U.S. Pat. No.6,395,845, which discloses the use of epoxy resin-based waterproofingsheets; WO 94/04349, which discloses the use of flexible protectivewaterproofing sheets composed by a flexible polymeric foil impregnatedwith a cement binder-based material; EP 0794299, in which a reference ismade about production method of flat covering can be obtained byapplying two coatings of a cement binder-latex mix reinforced, in themiddle, by a perforated polypropylene sheet.

A principal aim of the present invention is therefore to solve thedescribed problems, eliminating the drawbacks of the mentioned priorart, by providing a method that allows the production of a continuouswaterproofing flooring on flat roofs, terraces, balconies and other flatstructures.

Within the scope of this aim, an important object of the presentinvention is to provide a continuous waterproofing flooring that can beapplied on any surface, new or old, constituted by cement foundation,different kinds of tiles or natural and artificial stone coverings.

Another object of the present invention is to provide a continuouswaterproofing flooring that can be applied even on wet foundation andwith temperatures down to +0.5° C.

Another object of the present invention is to provide a continuouswaterproofing flooring suitable for pedestrian and light vehicle use(with mass up to 3.5 tons), self-cleaning, nonslip, not subject toyellowing, wear and tear resistant.

Another object of the present invention is to provide a continuouswaterproofing flooring that can be produced on site and in only twosteps with a short interval of time between them.

This aim, these objects and others which will become apparenthereinafter are achieved by providing a method for producing acontinuous waterproofing flooring, characterized in that it comprisesthe following steps:

-   -   a) a first step consisting in laying, on a previously prepared        foundation, a layer of two-component liquid applied        waterproofing membrane based on a hydraulic binder-latex mix, or        laying a layer of two-component liquid applied waterproofing        membrane based on hydraulic binder-latex mix followed by the        laying and impregnation with the same liquid mix of a fibrous        reinforcing base layer or matting;    -   b) a second step consisting in coating of the above described        waterproofing membrane with a mix of polymers, additives, and        eventually aggregates.

Further characteristics and advantages of the invention will becomeapparent evident from the following detailed description of a particularstructure thereof, illustrated only by way of non-limitative example inthe accompanying drawings, wherein:

FIG. 1 is a perspective view of the flooring;

FIG. 2 is a sectional view of the flooring of FIG. 1.

With reference to the above figures, the reference numeral 1 designatesa continuous waterproofing flooring for a previously prepared foundation2 that is constituted by a base provided for example by means of aconcrete casting.

The continuous waterproofing flooring is produced on site and entailsthe execution of both the above mentioned steps.

The first step consists in laying the layer 3 (two-component liquidapplied waterproofing membrane based on a hydraulic binder-latex mix) onfoundation 2. The two-component liquid applied waterproofing membranebased on a hydraulic binder-latex mix is composed of a mix ofaggregates, additives, hydraulic binders, polymer latices and waterobtained by mixing the dry and liquid components. Therefore theresulting material is composed of a mix of water, hydraulic binders andat least one polymer latex, for example styrene-acrylic esters latex. Ifnecessary, just after the application of layer 3 is completed, you canproceed to lay a fibrous reinforcing base layer or matting 4 that can beconstituited by non-woven fabric, felt, matting or any other structurethat allows impregnation by and incorporation in layer 3; in this caseit is advisable to lay on the fibrous reinforcing base layer or matting4 a finishing layer 5 made of the same liquid mix. The interposition ofthe fibrous reinforcing base layer or matting 4 between the two layersof liquid mix allows to increase the tensile-strength characteristics oflayer 3 and it should not alter the water vapor permeability of thesystem. Layers 3, 4 and 5 all together are waterproofing and water vaporpermeable, so as to allow the laying of the system even on wetfoundation. These characteristics are provided only by layer 3 when theliquid mix is applied without the fibrous reinforcing base layer ormatting 4.

The second step consists in laying, on layer 5 (or 3, if the fibrousreinforcing base layer or matting 4 is not present), a pigmented ortransparent mix of polymers and additives characterized by high watervapor permeability; this mix could eventually contain natural orartificial, coloured or not, aggregates.

The system obtained by laying the different components as described inthe first and the second step, is the continuous waterproofing flooring,that is the object of the present invention.

The dimensions constituting the individual components of the productobtained with the present method can of course be the most appropriateaccording to the specific requirements.

Obviously, the method provided by the present invention is susceptibleof changes, all of them being within the same inventive concept.

1. A method for producing a continuous waterproofing flooringcharacterized in that it's obtainable exclusively by coupling twodistinct layers in according to the laying steps hereafter specified:1.a) the first layer consisting in laying, on a previously preparedfoundation, a composite system formed by a prefabricated fibrousreinforcing base layer or matting impregnated by a two-component liquidapplied mix based on polymer latices and hydraulic binders; 1.b) thesecond layer consisting in the coating of the above described firstlayer with a mix of polymers and additives, with or without any kind ofaggregates, so as to create the visible side of the walkable andvehicle-suitable flooring.
 2. (canceled)
 3. A method according to claim1, characterized in that said impregnating two-component liquid appliedmix of the composite system is composed by at least one polymer latexand one hydraulic binder.
 4. A method according to claim 1,characterized in that the first layer has the ability to bridge thecracks in the foundation without losing its waterproofing ability.
 5. Amethod according to claim 1, characterized in that said impregnatingtwo-component liquid applied mix of the composite system acts as awaterproofing agent for the foundation.
 6. A method according to claim1, characterized in that said impregnating two-component liquid appliedmix of the composite system makes the prefabricated fibrous reinforcingbase layer or matting adhere to the foundation.
 7. (canceled)
 8. Amethod according to claim 1, characterized in that said prefabricatedfibrous reinforcing base layer or matting can be made of woven-non-wovenmaterials obtained from staple or continuous fibre, chopped strandmatting, fibreglass net or net made of any kind of synthetic fibre,felt, mono-directional or multi-directional band made of carbon fibre,fibreglass or aromatic polyamides fibre, or any other material fit forthe purpose.
 9. A method according to claim 1, characterized in that atleast one component of the coating, constituting the visible side of thewalkable and vehicle-suitable flooring, is an acrylic polymer.
 10. Amethod according to claim 1, characterized in that at least onecomponent of the coating, constituting the visible side of the walkableand vehicle-suitable flooring, is a styrene-acrylic ester copolymer. 11.A method according to claim 1, characterized in that at least onecomponent of the coating, constituting the visible side of the walkableand vehicle-suitable flooring, is an epoxy polymer.
 12. A methodaccording to claim 1, characterized in that at least one component ofthe coating, constituting the visible side of the walkable andvehicle-suitable flooring, is a methacrylic polymer.
 13. A methodaccording to claim 1, characterized in that at least one component ofthe coating, constituting the visible side of the walkable andvehicle-suitable flooring, is an unsaturated polyester resin.
 14. Amethod according to claim 1, characterized in that at least onecomponent of the coating, constituting the visible side of a walkableand vehicle-suitable flooring, is a polyurethane resin.
 15. A methodaccording to claim 1, characterized in that the polymer resins in thecoating, constituting the visible side of the walkable andvehicle-suitable flooring, can be transparent, coloured or pigmented.16. (canceled)